Antenna evaluating apparatus for evaluating multiple wave of radio waves transmitted from scatterer antennas with function of substantially simultaneous stop and start

Technical field

The present invention relates to an antenna evaluating apparatus for evaluating a performance of an antenna of a wireless communication apparatus, and to an antenna evaluating method using the antenna evaluating apparatus.

Background art

Conventionally, there has been proposed an antenna evaluating apparatus which has a plurality of transmitting antennas (referred to as scatterer antennas hereinafter) for modeling scatterers. The transmitting antennas are provided on the circumference of a circle at equal spaces, where the circle has a predetermined radius, and the antenna evaluating apparatus generates a spatial multiple wave in the vicinity of the center of installation positions of the scatterer antennas (See Patent Document 1 and the Non-Patent Documents 1 to 4, for example). In such an antenna evaluating apparatus, a transmitting signal generated by a signal generator is divided into transmitting signals of the same number as that of the scatterer antennas, and divided transmitting signals are radiated from corresponding scatterer antennas via respective phase shifters and attenuators. In this case, by adjusting phase shift amounts of the respective phase shifters and the attenuation amounts of the respective attenuators, a desired fading environment such as a Rayleigh fading environment can be generated at the center of the installation positions the respective scatterer antennas. Therefore, by placing a receiving antenna to be evaluated at the center of the installation position of the respective scatterer antennas, the performance of the receiving antenna under the fading environment can be evaluated based on a received signal received by the receiving antenna.

Citation list

Patent Document

Patent Document 1: Japanese patent laid-open publication No. JP-2005-227213A.

Non-Patent Document

Non-Patent Document 1: Tsutomu Sakata, et al., "Evaluation of Mobile Terminal Antennas Using Spatial Fading Emulator", Matsushita Technical Journal, Vol. 52, No. 5, pp. 70-75, October, 2006. Non-Patent Document 2: Tsutomu Sakata, et al., "Channel Capacity Measurements of a MIMO Antenna under a Rayleigh-fading Channel by a Spatial Fading Emulator", Proceedings of the Institute of Electronics, Information and Communication Engineers 2007 Society Conference, B-1-9, September, 2007. Non-Patent Document 3: Tsutomu Sakata et al., "A Multipath Measurement System with a Variable Power Angular Spectrum for Handset MIMO Antennas", Technical Report of the Institute of Electronics, Information and Communication Engineers, Vol. 108, No. 5, pp. 13-18, April, 2008. Non-Patent Document 4: Tsutomu Sakata et al., "An Evaluation of the MIMO Transmission Characteristics in a Cluster Propagation Environment Using a Spatial Fading Emulator", Technical Report of the Institute of Electronics, Information and Communication Engineers, Vol. 108, No. 429, pp. 121-126, April, 2009.

Summary of invention

Technical Problem

FIG. 19 is a graph showing one example of a received power received by using the prior art antenna evaluating apparatus. Referring to FIG. 19, f.sub.D is a Doppler frequency, and `t` is time. Conventionally, an amplitude and a phase of a received signal were measured within an arbitrary measurement time interval T1, T2 or T3 in a time interval in which a desired fading environment is generated by using the antenna evaluating apparatus. In this case, in order to increase a reproducibility of the fading environment, it was required to set a duration of the measurement time interval sufficiently longer than a time cycle of the variation of the received signal. For example, as shown in FIG. 19, when the duration of the measurement time interval is not set sufficiently longer than the time cycle of the variation of the received signal, statistical properties such as average values of the received signal in the respective measurement time intervals become different from each other even when the durations of the measurement time intervals T1, T2 and T3 are the same as each other. This leads to such a problem that an evaluation accuracy of the receiving antenna becomes lower when the duration of the measurement time interval is shortened.

It is an object of the present invention is to provide an antenna evaluating apparatus and method each capable of solving the above problems and capable of executing evaluation of a receiving antenna in a time shorter than that of the prior art with an accuracy higher than that of the prior art.

Solution to Problem

An antenna evaluating apparatus according to a first invention includes a plurality of N scatterer antennas provided at predetermined positions different from each other, respectively, signal generator means for generating a predetermined transmitting signal, transmitter means, and receiver means. The transmitter means divides the transmitting signal into a plurality of N transmitting signals, changes at least one of a phase and an amplitude of each of divided transmitting signals, and radiates changed transmitting signals as radio waves from the scatterer antennas corresponding to the changed transmitting signals, respectively. The receiver means receives a multiple wave of radiated radio waves by using a receiving antenna to be evaluated and placed substantially at a center of the respective positions. The antenna evaluating apparatus includes controller means for substantially simultaneously starting operations of evaluation means including the signal generator means, the transmitter means and the receiver means, and evaluates a performance of the receiving antenna based on a received multiple wave.

In the above-described antenna evaluating apparatus, the controller means substantially simultaneously stops the operations of the signal generator means and the receiver means excluding the transmitter means.

In addition, the above-described antenna evaluating apparatus includes at least one signal generator means, at least one transmitter means, and at least one receiver means. When evaluating the receiving antenna, the controller means (a) from the at least one signal generator means, selects at least one signal generator means as evaluation means used for an evaluation, (b) from the at least one transmitter means, selects at least one transmitter means as evaluation means used for the evaluation, (c) from the at least one receiver means, selects at least one receiver means as evaluation means used for the evaluation, and substantially simultaneously starts the operations of selected evaluation means.

Further, in the above-described antenna evaluating apparatus, the controller means substantially simultaneously stops the operations of the signal generator means and the receiver means excluding the transmitter means among the selected evaluation means.

Still further, the above-mentioned antenna evaluating apparatus further includes trigger generator means for generating a trigger signal in response to a trigger generation request signal from the controller means, and outputting the trigger signal to the evaluation means. The controller means generates the trigger generation request signal, and outputs the trigger generation request signal to the trigger generator means, and the evaluation means substantially simultaneously starts the respective operations in response to the trigger signal.

In addition, in the above-described antenna evaluating apparatus, the controller means further includes trigger generator means for generating a trigger signal, and outputting the trigger signal to the evaluation means. The evaluation means substantially simultaneously starts the respective operations in response to the trigger signal.

In an antenna evaluating method using an antenna evaluating apparatus according to a second invention, the antenna evaluating apparatus includes a plurality of N scatterer antennas provided at predetermined positions different from each other, respectively, signal generator means for generating a predetermined transmitting signal, transmitter means, and receiver means. The transmitter means divides the transmitting signal into a plurality of N transmitting signals, changes at least one of a phase and an amplitude of each of divided transmitting signals, and radiates changed transmitting signals as radio waves from the scatterer antennas corresponding to the changed transmitting signals, respectively. The receiver means receives a multiple wave of radiated radio waves by using a receiving antenna to be evaluated and placed substantially at a center of the respective positions. The antenna evaluating method includes a control step of substantially simultaneously starting operations of evaluation means including the signal generator means, the transmitter means and the receiver means, and evaluating a performance of the receiving antenna based on a received multiple wave.

In the above-described antenna evaluating method, the control step further includes a step of substantially simultaneously stopping the operations of the signal generator means and the receiver means excluding the transmitter means.

In addition, in the above-described antenna evaluating method, the antenna evaluating apparatus includes at least one signal generator means, at least one transmitter means, and at least one receiver means. When evaluating the receiving antenna, the control step (a) from the at least one signal generator means, selects at least one signal generator means as evaluation means used for an evaluation, (b) from the at least one transmitter means, selects at least one transmitter means as evaluation means used for the evaluation, (c) from the at least one receiver means, selects at least one receiver means as evaluation means used for the evaluation, and substantially simultaneously starts the operations of selected evaluation means.

Further, in the above-described antenna evaluating method, the control step further includes a step of substantially simultaneously stopping the operations of the signal generator means and the receiver means excluding the transmitter means among the selected evaluation means.

Still further, in the above-described antenna evaluating method, the antenna evaluation apparatus further includes trigger generator means for generating a trigger signal in response to a trigger generation request signal, and outputting the trigger signal to the evaluation means. The control step further includes a step of generating the trigger generation request signal, and outputting the trigger generation request signal to the trigger generator means. The evaluation means substantially simultaneously starts the respective operations in response to the trigger signal.

In addition, in the above-described antenna evaluating method, the control step further includes a step of generating a trigger signal, and outputting the trigger signal to the evaluation means. The evaluation means substantially simultaneously starts the respective operations in response to the trigger signal.

Advantageous Effects of Invention

According to the antenna evaluating apparatus and method of the present invention, the operations of the evaluator means including the signal generator means, the transmitter means and the receiver means used for evaluating the performance of a receiving antenna are substantially simultaneously started, and the performance of the receiving antenna is evaluated based on the received multiple wave. Therefore, it is possible to generate a multiple wave with higher reproducibility at the installation position of the receiving antenna, and to execute the evaluation of the receiving antenna in a time shorter than that of the prior art with an accuracy higher than that of the prior art.

Brief description of drawings

FIG. 1 is a perspective view showing an essential part of a configuration of an antenna evaluating apparatus according to a first preferred embodiment of the present invention;

FIG. 2 is a block diagram showing a configuration of a multiple wave controlling and measuring apparatus 200A of FIG. 1;

FIG. 3 is a sequence diagram showing an antenna evaluating process executed by the multiple wave controlling and measuring apparatus 200A of FIG. 2;

FIG. 4 is a block diagram showing a configuration of a multiple wave controlling and measuring apparatus 200B according to a second preferred embodiment of the present invention;

FIG. 5 is a sequence diagram showing an antenna evaluating process executed by the multiple wave controlling and measuring apparatus 200B of FIG. 4;

FIG. 6 is a block diagram showing a configuration of a multiple wave controlling and measuring apparatus 200C according to a third preferred embodiment of the present invention;

FIG. 7 is a sequence diagram showing an antenna evaluating process executed by the multiple wave controlling and measuring apparatus 200C of FIG. 6;

FIG. 8 is block diagram showing a configuration of a multiple wave controlling and measuring apparatus 200D according to a fourth preferred embodiment of the present invention;

FIG. 9 is a sequence diagram showing an antenna evaluating process executed by the multiple wave controlling and measuring apparatus 200D of FIG. 8;

FIG. 10 is a perspective view of a receiving antenna support base 102A according to a fifth preferred embodiment of the present invention;

FIG. 11 is a block diagram showing a configuration of a multiple wave controlling and measuring apparatus 200E according to a modified preferred embodiment of the first preferred embodiment of the present invention;

FIG. 12 is a sequence diagram showing an antenna evaluating process executed by the multiple wave controlling and measuring apparatus 200E of FIG. 11;

FIG. 13 is a block diagram showing a configuration of a multiple wave controlling and measuring apparatus 200F according to a modified preferred embodiment of the second preferred embodiment of the present invention;

FIG. 14 is a sequence diagram showing an antenna evaluating process executed by the multiple wave controlling and measuring apparatus 200F of FIG. 13;

FIG. 15 is a block diagram showing a configuration of a multiple wave controlling and measuring apparatus 200G according to a modified preferred embodiment of the third preferred embodiment of the present invention;

FIG. 16 is a sequence diagram showing an antenna evaluating process executed by the multiple wave controlling and measuring apparatus 200G of FIG. 15;

FIG. 17 is a block diagram showing a configuration of a multiple wave controlling and measuring apparatus 200H according to a modified preferred embodiment of the fourth preferred embodiment of the present invention;

FIG. 18 is a sequence diagram showing an antenna evaluating process executed by the multiple wave controlling and measuring apparatus 200H of FIG. 17; and

FIG. 19 is a graph showing one example of a received power received by using a prior art antenna evaluating apparatus.

Description of embodiments

Preferred embodiments according to the present invention will be described below with reference to the attached drawings. Components similar to each other are denoted by the same reference numerals and will not be described herein in detail.

First Preferred Embodiment

FIG. 1 is a perspective view showing an essential part of a configuration of an antenna evaluating apparatus (also referred to as a spatial multiple wave generating apparatus or a fading emulator) according to the first preferred embodiment of the present invention, and FIG. 2 is a block diagram showing a configuration of a multiple wave controlling and measuring apparatus 200A of FIG. 1. FIG. 3 is a sequence diagram showing an antenna evaluating process executed by the multiple wave controlling and measuring apparatus 200A of FIG. 2.

As described in detail later, the antenna evaluating apparatus of the present preferred embodiment includes seven scatterer antennas 50a-1 to 50a-7 provided at predetermined positions different from each other, respectively, a signal generator 22a for generating a transmitting signal S22a, a transmitter circuit 30a, and a receiver 21a. The transmitter circuit 30a divides the transmitting signal S22a into seven transmitting signals, changes a phase and an amplitude of each of divided transmitting signals, and radiates changed transmitting signals as radio waves from the respective scatterer antennas 50a-1 to 50a-7 corresponding to the changed transmitting signals, respectively. The receiver 21a receives a multiple wave of radiated radio waves by using a receiving antenna 60a to be evaluated and placed substantially at a center of the installation positions of the scatterer antennas 50a-1 to 50a-7. The antenna evaluating apparatus is characterized by including a computer 10 for substantially simultaneously starting operations of an evaluation circuit 80A, which includes the signal generator 22a, a D/A converter 11a of the transmitter circuit 30a, and the receiver 21a used for evaluating the performance of the receiving antenna 60a, and evaluates the performance of the receiving antenna 60a based on the received multiple wave.

Referring to FIG. 1, the antenna evaluating apparatus of the present preferred embodiment is installed in an anechoic chamber, and configured by including the scatterer antennas 50a-1 to 50a-7, each of which is a half-wave dipole antenna, and the multiple wave controlling and measuring apparatus 200A. In the present preferred embodiment, the receiving antenna 60a to be evaluated is a half-wave dipole antenna that receives vertically polarized radio waves. The scatterer antennas 50a-1 to 50a-7 are vertically installed at positions at vertex portions of a scatterer antenna support base 101 assembled in a frame having a shape of a regular heptagon pillar, so that heights of feeding points of the scatterer antennas 50a-1 to 50a-7 are "H" from the floor surface and vertically polarized radio waves are radiated from the scatterer antennas 50a-1 to 50a-7. With this arrangement, the scatterer antennas 50a-1 to 50a-7 are provided on the circumference of a circle of a radius "R" at equal spaces. In this case, the origin of a right-handed XYZ coordinate system is defined to the center of the positions of the feeding points of the respective scatterer, the positive direction of the Z-axis is defined to an upward direction with respect to the origin, and the positive direction of the Y-axis is defined to a direction directed from the origin toward the scatterer antenna 50a-1. The receiving antenna 60a is vertically installed at a vertex portion of a receiving antenna support base 102 of a pole, so that the feeding point of the receiving antenna 60a positioned at the origin and the vertically polarized radio waves are received by the receiving antenna 60a. In the present preferred embodiment, the scatterer antenna support base 101 and the receiving antenna support base 102 are formed of a resin material such as polypropylene or vinyl chloride. In addition, the height "H" of each of the feeding points of the scatterer antennas 50a-1 to 50a-7 and the receiving antenna 60a measured from the floor surface is set to 1.5 m, and a distance "R" of each of the feeding points measured from the origin is set to 1.5 m.

Referring to FIG. 2, the multiple wave controlling and measuring apparatus 200A is configured by including the computer 10, a network analyzer 20a including the receiver 21a and the signal generator 22a, the transmitter circuit 30a, and a trigger generator circuit 70. Further, the transmitter circuit 30a is configured by including a D/A converter 11a, a divider 12a, a phase shifter circuit 13a, and an attenuator circuit 14a. The phase shifter circuit 13a includes phase shifters 13a-1 to 13a-7 provided for the scatterer antennas 50a-1 to 50a-7, respectively, and the attenuator circuit 14a includes attenuators 14a-1 to 14a-7 provided for the scatterer antennas 50a-1 to 50a-7, respectively. The signal generator 20a, the transmitter circuit 30a and the receiver 21a constitute the evaluation circuit 80A for evaluating the performance of the receiving antenna 60a. In this case, upon receiving a trigger generation request signal S10t from the computer 10, the trigger generator circuit 70 generates a trigger signal S70, and outputs the same signal to at least one of the D/A converter 11a, the signal generator 22a and the receiver 21a. In addition, the network analyzer 20a is set to a single frequency mode in which the signal generator 22a generates a transmitting signal S22a of an unmodulated continuous wave signal having a frequency of 2.14 GHz, a transmission output level is set to +5 dBm, and a screen display is set to a polar coordinate display of a scattering parameter S21. In this case, the network analyzer 20a has an output terminal of a port 1 and an input terminal of a port 2. In addition, the signal generator 22a and the receiver 21a is set so as to start or end signal generating process and receiving process, respectively, in response to an inputted trigger signal S70.

The signal generator 22a starts generating the transmitting signal S22a in response to the trigger signal S70, and outputs the transmitting signal S22a to the divider 12a. The transmitting signal S22a is divided into seven transmitting signals by the divider 12a, and the seven transmitting signals are outputted to the phase shifters 13a-1 to 13a-7, respectively. Each of the phase shifters 13a-1 to 13a-7 shifts the phase of an inputted transmitting signal by a predetermined phase shift amount corresponding to a phase shift amount control voltage from the D/A converter 11a, and outputs a resulting signal to a corresponding one of the attenuators 14a-1 to 14a-7. Each of the attenuators 14a-1 to 14a-7 attenuates an inputted phase-shifted transmitting signals by a predetermined attenuation amount corresponding to an attenuation amount control voltage from the D/A converter 11a, and radiate a resulting signal as a vertically polarized radio wave from a corresponding one of the scatterer antennas 50a-1 to 50a-7 provided for the attenuators 14a-1 to 14a-7, respectively. In this case, since the antenna evaluating apparatus of FIG. 1 is installed in the anechoic chamber, influences of reflected waves reflected on the ceiling, the floor surface, the walls and so on are sufficiently smaller than those of direct waves, and a multiple wave composed of the direct waves radiated from the scatterer antennas 50a-1 to 50a-7 are generated at the installation position of the receiving antenna 60a.

The computer 10 calculates the phase shift amounts of the respective phase shifters 13a-1 to 13a-7 and the attenuation amounts of the respective attenuators 14a-1 to 14a-7, so that the multiple wave in a desired fading environment of such as Rayleigh fading or Nakagami-Rice fading is generated at the installation position of the receiving antenna 60a. Then, the computer 10 generates a digital multiple wave control signal including the phase shift amount control voltages corresponding to calculated phase shift amounts, the attenuation amount control voltages corresponding to calculated attenuation amounts and a measurement time interval Tm, in which the multiple wave is generated, and outputs the digital multiple wave control signal to the D/A converter 11a. In this case, a phase change amount Pn(t) of the radio wave radiated from the n-th (n=1, 2, . . . , N; and N=7 in the present preferred embodiment) scatterer antenna 50a-n is given by the following equation: Pn(t)=2.pi.f.sub.Dt cos(.phi.n+.phi.shift)+.alpha.n, Equation 1:

where, f.sub.D denotes a Doppler frequency, .phi.n denotes an azimuth of the scatterer antenna 50a-n when seen from the receiving antenna 60a, .phi.shift denotes an azimuth of a traveling direction of the receiving antenna 60a, and .alpha.n denotes an initial phase. An azimuth .phi.1 of the scatterer antenna 50a-1 when seen from the receiving antenna 60a is defined to zero degrees, and the azimuths .phi.n and .phi.shift are measured clockwise with respect to the receiving antenna 60a. In addition, the initial phase .alpha.n is determined by using uniform random numbers.

In response to the trigger signal S70, the D/A converter 11a starts a D/A conversion process for converting an inputted multiple wave control signal into the analog phase shift amount control voltages corresponding to the phase shift amounts of the phase shifters 13a-1 to 13a-7, respectively, and the analog attenuation amount control voltages corresponding to the attenuation amounts of the attenuators 14a-1 to 14a-7, respectively. The D/A converter 11a outputs the analog phase shift amount control voltages to the phase shifters 13a-1 to 13a-7, respectively, and outputs the analog attenuation amount control voltages to the attenuators 14a-1 to 14a-7, respectively. In this case, the period of the D/A conversion process is set to a predetermined measurement time interval Tm. It is noted that the start timing of the D/A conversion process by the D/A converter 11a is the start timing of wireless transmission operation by the transmitter circuit 30a. In response to the trigger signal S70, the receiver 21a starts the receiving process for receiving the multiple wave of the radio waves radiated by the scatterer antennas 50a-1 to 50a-7 by using the receiving antenna 60a and measuring the amplitude and the phase of the received signal, and outputs received data including data of measured amplitudes and measured phases to the computer 10. The computer 10 evaluates the performance of the receiving antenna 60a based on the received data from the receiver 21a.

Next, with reference to FIG. 3, the antenna evaluating process executed by the multiple wave controlling and measuring apparatus 200A of FIG. 2 is described. First of all, the computer 10 generates the multiple wave control signal, and outputs the same signal to the D/A converter 11a. In response to this, the D/A converter 11a is put into a trigger wait state. Further, the computer 10 outputs trigger wait instruction signals, each of which represents an instruction to wait for the trigger signal S70, to the signal generator 22a and the receiver 21a. In response to this, the signal generator 22a and the receiver 21a are each put into the trigger wait state. Next, the computer 10 outputs the trigger generation request signal S10t to the trigger generator circuit 70, where the trigger generation request signal S10t represents an instruction to substantially simultaneously output the trigger signal S70 to the D/A converter 11a, the signal generator 22a and the receiver 21a. In response to this, the trigger generator circuit 70 generates the trigger signal S70, and substantially simultaneously outputs the same signal to the D/A converter 11a, the signal generator 22a and the receiver 21a.

In response to the trigger signal S70, the D/A converter 11a starts the D/A conversion process for converting the multiple wave control signal received from the computer 10 into the phase shift amount control voltages for the phase shifters 13a-1 to 13a-7 and attenuation amount control voltages for the attenuators 14a-1 to 14a-7. By this operation, the transmitter circuit 30a starts the wireless transmission operation. Then, the D/A converter 11a stops the D/A conversion process when the measurement time interval Tm has elapsed, and outputs a multiple wave generation termination notify signal to the computer 10, where the multiple wave generation termination notify signal represents a notification that the generation of the multiple wave has been stopped. On the other hand, in response to the trigger signal S70, the signal generator 22a and the receiver 21a start the signal generating process and the receiving process, respectively. In this case, the D/A conversion process, the signal generating process and the receiving process are started substantially simultaneously.

In response to the multiple wave generation termination notify signal, the computer 10 outputs the trigger generation request signal S10t to the trigger generator circuit 70, where the trigger generation request signal S10t represents an instruction to substantially simultaneously output the trigger signal S70 to the signal generator 22a and the receiver 21a. In response to this, the trigger generator circuit 70 generates the trigger signal S70, and substantially simultaneously outputs the same signal to the signal generator 22a and the receiver 21a. In response to this, the signal generator 22a and the receiver 21a substantially simultaneously stop the signal generating process and the receiving process, respectively. Further, the receiver 21a outputs the received data including the data of measured amplitudes and measured phases to the computer 10. The computer 10 evaluates the performance of the receiving antenna 60a based on the received data from the receiver 21a.

As described above in detail, according to the present preferred embodiment, the D/A converter 11a, the signal generator 22a and the receiver 21a substantially simultaneously starts the D/A conversion process, the signal generating process and the receiving process, respectively, in response to the trigger signal S70. Namely, the operation start timings of the signal generator 22a, the transmitter circuit 30a and the receiver 21a constituting the evaluation circuit 80A are substantially synchronized with each other. Therefore, only by setting the initial phases .alpha.n of the radio wave transmitted from each scatterer antenna 50a-n in different antenna evaluating processes to be the same as each other, the multiple waves substantially the same as each other can be generated at the installation position of the receiving antenna 60a. Further, since it is possible to generate the multiple waves substantially the same as each other in each antenna evaluating process with higher reproducibility than that of the prior art, the measurement time interval Tm can be made shorter than that of the prior art. Therefore, the receiving antenna 60a can be evaluated in a time shorter than that of the prior art with an accuracy higher than that of the prior art. According to the present preferred embodiment, even when, for example, the receiving antenna 60a is replaced with another receiving antenna, a multiple wave substantially the same as the multiple wave received by the receiving antenna 60a can be received by the another receiving antenna.

In addition, according to the present preferred embodiment, the D/A conversion process, the signal generating process and the receiving process can be automatically started only by outputting the trigger generation request signal S10t to the trigger generator circuit 70 after putting the D/A converter 11a, the signal generator 22a and the receiver 21a into the trigger wait state.

Second Preferred Embodiment

FIG. 4 is a block diagram showing a configuration of a multiple wave controlling and measuring apparatus 200B according to the second preferred embodiment of the present invention, and FIG. 5 is a sequence diagram showing an antenna evaluating process executed by the multiple wave controlling and measuring apparatus 200B of FIG. 4. The multiple wave controlling and measuring apparatus 200B is characterized by further including a network analyzer 20b including a receiver 21b, as compared with the multiple wave controlling and measuring apparatus 200A of the first preferred embodiment. Further, in the present preferred embodiment, the receiving antenna to be evaluated is a diversity antenna 60d including the receiving antenna 60a and a receiving antenna 60b of a half-wave dipole antenna for receiving vertically polarized radio waves.

The receiving antennas 60a and 60b are vertically provided at the vertex portion of the receiving antenna support base 102 so that the feeding points of the receiving antennas 60a and 60b are positioned at a coordinate position (0, .lamda./4, 0) and a coordinate position (0, -.lamda./4, 0), respectively, in the XYZ coordinate system and vertically polarized radio waves are received by the receiving antennas 60a and 60b. It is noted that .lamda. is the wavelength of the radio waves radiated from the scatterer antennas 50a-1 to 50a-7. The receiving antennas 60a and 60b constitute the diversity antenna 60d. In addition, upon receiving the trigger generation request signal S10t from the computer 10, the trigger generator circuit 70 generates the trigger signal S70, and outputs the same signal to at least one of the D/A converter 11a, the signal generator 22a and the receivers 21a and 21b. Further, in the network analyzer 20b, the receiver 21b is set so as to start or end the receiving process is started in response to the inputted trigger signal S70 in a manner similar to that of the receiver 21a. In addition, the receiver 21b receives the multiple wave of the radio waves radiated by the scatterer antennas 50a-1 to 50a-7 by using the receiving antenna 60b, and measures the amplitude and the phase of the received signal in the receiving process. Then, the received data including the data of measured amplitudes and measured phases are outputted to the computer 10. It is noted that the signal generator 20a, the transmitter circuit 30a, the receiver 21a and the receiver 21b constitute an evaluation circuit 80B for evaluating the performance of the diversity antenna 60d.

Next, with reference to FIG. 5, the antenna evaluating process executed by the multiple wave controlling and measuring apparatus 200B of FIG. 4 is described. First of all, the computer 10 generates the multiple wave control signal, and outputs the same signal to the D/A converter 11a. In response to this, the D/A converter 11a is put into the trigger wait state. Further, the computer 10 outputs the trigger wait instruction signals, each of which represents an instruction to wait for the trigger signal S70, to the signal generator 22a and the receivers 21a and 21b. In response to this, the signal generator 22a and the receivers 21a and 21b are each put into the trigger wait state. Next, the computer 10 outputs the trigger generation request signal S10t to the trigger generator circuit 70, where the trigger generation request signal S10t represents an instruction to substantially simultaneously output the trigger signal S70 to the D/A converter 11a, the signal generator 22a and receivers 21a and 21b. In response to this, the trigger generator circuit 70 generates the trigger signal S70, and substantially simultaneously outputs the same signal to the D/A converter 11a, the signal generator 22a and the receivers 21a and 21b.

In response to the trigger signal S70, the D/A converter 11a starts the D/A conversion process for converting the multiple wave control signal received from the computer 10 into the phase shift amount control voltages for the phase shifters 13a-1 to 13a-7 and the attenuation amount control voltages for the attenuators 14a-1 to 14a-7. By this operation, the transmitter circuit 30a starts the wireless transmission operation. Then, the D/A converter 11a stops the D/A conversion process when the measurement time interval Tm has elapsed, and outputs the multiple wave generation termination notify signal to the computer 10, where the multiple wave generation termination notify signal represents a notification that the generation of the multiple wave has been stopped. On the other hand, in response to the trigger signal S70, the signal generator 22a starts the signal generating process. In addition, in response to the trigger signal S70, each of the receivers 21a and 21b starts the receiving process. In this case, the D/A conversion process, the signal generating process and the receiving process by the receivers 21a and 21b are started substantially simultaneously.

In response to the multiple wave generation termination notify signal, the computer 10 outputs the trigger generation request signal S10t to the trigger generator circuit 70, where the trigger generation request signal S10t represents an instruction to substantially simultaneously output the trigger signal S70 to the signal generator 22a and the receivers 21a and 21b. In response to this, the trigger generator circuit 70 generates the trigger signal S70, and substantially simultaneously outputs the same signal to the signal generator 22a and the receivers 21a and 21b. In response to this, the signal generator 22a and the receivers 21a and 21b substantially simultaneously stop the signal generating process and the receiving process, respectively. Further, the receivers 21a and 21b output the received data including the data of the measured amplitudes and measured phases, respectively, to the computer 10. The computer 10 evaluates the performance of the diversity antenna 60d based on the received data from each of the receivers 21a and 21b.

As described above in detail, according to the present preferred embodiment, the D/A converter 11a, the signal generator 22a and the receivers 21a and 21b substantially simultaneously starts the D/A conversion process, the signal generating process and the receiving processes, respectively, in response to the trigger signal S70. Namely, the operation start timings of the signal generator 22a, the transmitter circuit 30a and the receivers 21a and 21b constituting the evaluation circuit 80B are substantially synchronized with each other. Therefore, only by setting the initial phases .alpha.n of the radio wave transmitted from each scatterer antenna 50a-n in different antenna evaluating processes to be the same as each other, the multiple waves substantially the same as each other can be generated at the installation position of the diversity antenna 60d. Further, since it is possible to generate the multiple waves substantially the same as each other in each antenna evaluating process with higher reproducibility than that of the prior art, the measurement time interval Tm can be made shorter than that of the prior art. Therefore, the diversity antenna 60d can be evaluated in a time shorter than that of the prior art with an accuracy higher than that of the prior art.

In the present preferred embodiment, the diversity antenna 60d includes the two receiving antennas 60a and 60b, however, the present invention is not limited to this. The diversity antenna 60d may include a plurality of three or more receiving antennas. In this case, it is proper to provide a network analyzer configured in a manner similar to that of the network analyzer 20b for each additional receiving antenna, and to synchronize the receiving process start timings of the network analyzers with each other.

Third Preferred Embodiment

FIG. 6 is a block diagram showing a configuration of a multiple wave controlling and measuring apparatus 200C according to the third preferred embodiment of the present invention, and FIG. 7 is a sequence diagram showing an antenna evaluating process executed by the multiple wave controlling and measuring apparatus 200C of FIG. 6. The multiple wave controlling and measuring apparatus 200C of the present preferred embodiment is characterized by further including scatterer antennas 50b-1 to 50b-7 that are half-wave dipole antennas, a divider 40 and a transmitter circuit 30b, as compared with the multiple wave controlling and measuring apparatus 200A of the first preferred embodiment. In this case, the transmitter circuit 30b is configured by including a D/A converter 11b, a divider 12b, a phase shifter circuit 13b including phase shifters 13b-1 to 13b-7 provided for the scatterer antennas 50b-1 to 50b-7, respectively, and an attenuator circuit 14b including attenuators 14b-1 to 14b-7 provided for the scatterer antennas 50b-1 to 50b-7, respectively. It is noted that the signal generator 20a, the transmitter circuits 30a and 30b and the receiver 21a constitute an evaluation circuit 80C for evaluating the performance of the receiving antenna 60a.

The description continues in the full USPTO document.